The aim of this proposal is to develop the next generation of miniature, high- density multi-channel connectors suitable for chronic implantation in a patient's body as part of systems that are used, for example, to treat disorders of the peripheral nervous system. Maladies that could be treated in this way are problems with walking, such as after a stroke, and restoring natural sensations in a phantom limb after amputation. In this study, we will use custom-microfabricated connector bodies to facilitate interconnections within and among long-lasting neural interfaces. Custom packaging and assembly methods for the miniature connectors will also be developed. The tasks to be accomplished under this proposal include the fabrication of new HD connectors for mating with pre-existing micro-neurostimulator designs. We will also evaluate the long- term biocompatibility and bio-stability of these connectors through both in vitro experiments and animal surgical trials. The data collected will facilitate future application to the FDA to do follow-on clinical studies of medical devices incorporating high density connector technology. The relationship between the proposed effort and the patient care mission of the VA is that these improvements are expected to increase the interchangeability of components of implantable neurostimulation systems for rehabilitation that have high channel counts. This will improve new devices under development such as implantable walking aids and devices for restoring natural sensation in amputated limbs.